It's a good idea to measure from the engine crank to the ground with plane level. Calculate what size prop you will be using, as in 11, 12 diameter. Give yourself enough clearance for you prop and measure for your struts and wheels.

You don't want to make the struts too short or you will end up using a smaller prop than you would have normally. It's a real PITA when you have cut all your wheel wells and find out you didn't allow clearance for the prop.

Frank